Thomas Hills

Thomas Hills
The University of Warwick · Department of Psychology

Ph.D. Biology

About

113
Publications
27,636
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Introduction
Thomas Hills currently works at the Department of Psychology, The University of Warwick. Thomas does research in Quantitative Psychology, Cognitive Science and Behavioural Science.

Publications

Publications (113)
Article
Full-text available
Area‐restricted search is the capacity to change search effort adaptively in response to resource encounters or expectations, from directional exploration (global, extensive search) to focused exploitation (local, intensive search). This search pattern is used by numerous organisms, from worms and insects to humans, to find various targets, such as...
Article
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This study investigates the influence of semantic maturation on early lexical development by examining the impact of contextual diversity—known to influence semantic development—on word promotion from receptive to productive vocabularies (i.e., comprehension‐expression gap). Study 1 compares the vocabularies of 3685 American‐English‐speaking typica...
Chapter
Humans constantly search for and use information to solve a wide range of problems related to survival, social interactions, and learning. While it is clear that curiosity and the drive for knowledge occupies a central role in defining what being human means to ourselves, where does this desire to know the unknown come from? What is its purpose? An...
Article
How does the relation between two words create humor? In this article, we investigated the effect of global and local contrast on the humor of word pairs. We capitalized on the existence of psycholinguistic lexical norms by examining violations of expectations set up by typical patterns of English usage (global contrast) and within the local contex...
Article
Thinking is complex. Over the years, several types of methods and paradigms have developed across the psychological, cognitive, and neural sciences to study such complexity. A rapidly growing multidisciplinary quantitative field of network science offers quantitative methods to represent complex systems as networks, or graphs, and study the network...
Preprint
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Suicide remains a serious public-health concern that is difficult to accurately predict in real-world settings. To identify potential predictors of suicide, we examined the emotional content of suicide notes using methods from cognitive network science. Specifically, we compared the co-occurrence networks of suicide notes with those constructed out...
Preprint
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Most current affect scales and sentiment analysis on written text focus on quantifying valence (sentiment) -- the most primary dimension of emotion. However, emotions are broader and more complex than valence. Distinguishing negative emotions of similar valence could be important in contexts such as mental health. This project proposes a semi-super...
Article
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The spread of online conspiracy theories represents a serious threat to society. To understand the content of conspiracies, here we present the language of conspiracy (LOCO) corpus. LOCO is an 88-million-token corpus composed of topic-matched conspiracy ( N = 23,937) and mainstream ( N = 72,806) documents harvested from 150 websites. Mimicking inte...
Article
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This study compares the lexical composition of 118 children with autism spectrum disorder (ASD) aged 12 to 84 months with 4626 vocabulary-matched typically developing toddlers with and without language delay, aged 8 to 30 months. Children with ASD and late talkers showed a weaker noun bias. Additionally, differences were identified in the proportio...
Article
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The prevailing maximum likelihood estimators for inferring power law models from rank-frequency data are biased. The source of this bias is an inappropriate likelihood function. The correct likelihood function is derived and shown to be computationally intractable. A more computationally efficient method of approximate Bayesian computation (ABC) is...
Preprint
How does the relation between two words create humor? In this paper, we investigated the effect of global and local contrast on the humor of word pairs. We capitalized on the existence of psycholinguistic lexical norms by examining violations of expectations set up by typical patterns of English usage (global contrast) and within the local context...
Article
Cognitive researchers often carve cognition up into structures and processes. Cognitive processes operate on structures, like vehicles driving over a map. Language alongside semantic and episodic memory are proposed to have structure, as are perceptual systems. Over these structures, processes operate to construct memory and solve problems by retri...
Preprint
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Over the past 200 years, rising rates of information proliferation have created new environments for information competition and, consequently, new selective forces on information evolution. These forces influence the information diet available to consumers, who in turn choose what to consume, creating a feedback process similar to that seen in man...
Article
Lay abstract: Although preverbal and minimally verbal children with autism spectrum disorder represent a significant portion of the autism spectrum disorder population, we have a limited understanding of and characterization of them. Although it is a given that their lexical profiles contain fewer words, it is important to determine whether (a) th...
Article
Despite increasing life expectancy and high levels of welfare, health care, and public safety in most post-industrial countries, the public discourse often revolves around perceived threats. Terrorism, global pandemics, and environmental catastrophes are just a few of the risks that dominate media coverage. Is this public discourse on risk disconne...
Preprint
The prevailing Bayesian maximum likelihood estimators for inferring power law models from rank-frequency data are biased. The source of this bias is an inappropriate likelihood function. The correct likelihood function is derived and shown to be computationally intractable. A more computationally efficient method of approximate Bayesian computation...
Article
Full-text available
Biological and artificial intelligence (AI) are often defined by their capacity to achieve a hierarchy of short-term and long-term goals that require incorporating information over time and space at both local and global scales. More advanced forms of this capacity involve the adaptive modulation of integration across scales, which resolve computat...
Article
People and other animals can search for information inside their heads. Where does this ability come from, and what does it enable cognitive systems to do? In this article, we address the behavioral and cognitive similarities between search in external environments and internal environments (e.g., memory). These require both maplike representations...
Article
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Existing affect scales typically involve recognition of emotions from a predetermined emotion checklist. However, a recognition-based checklist may fail to capture sufficient breadth and specificity of an individual's recalled emotional experiences and may therefore miss emotions that frequently come to mind. More generally, how do recalled emotion...
Preprint
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Computations in biological and artificial intelligence incorporate both local and global temporal and spatial scales, and aim to achieve a hierarchy of short-term and long-term goals. Insight into the unique nature of biological computations come from phenomena such as history-dependent inertia in decision making, credit assignment biases, and choi...
Article
How, and how well, do people switch between exploration and exploitation to search for and accumulate resources? We study the decision processes underlying such exploration/exploitation trade‐offs using a novel card selection task that captures the common situation of searching among multiple resources (e.g., jobs) that can be exploited without dep...
Preprint
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Memory search has long been pictured as taking place on a high-dimensional landscape. However, if people are able to cut corners in this landscape by dynamically shifting attention between the space's dimensions to connect distant locations, then this may give rise to wormholes in memory much like those of Einstein-Rosen in external space. Alternat...
Article
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We present the first attempt to construct a long-run historical measure of subjective wellbeing using language corpora derived from millions of digitized books. While existing measures of subjective wellbeing go back to at most the 1970s, we can go back at least 200 years further using our methods. We analyse data for six countries (the USA, UK, Ge...
Article
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An amendment to this paper has been published and can be accessed via a link at the top of the paper.
Article
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Free will is an apparent paradox because it requires a historical identity to escape its history in a self-guided fashion. Philosophers have itemized design features necessary for this escape, scaling from action to agency and vice versa. These can be organized into a coherent framework that neurocognitive capacities provide and that form a basis f...
Article
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The field of cognitive aging has seen considerable advances in describing the linguistic and semantic changes that happen during the adult life span to uncover the structure of the mental lexicon (i.e., the mental repository of lexical and conceptual representations). Nevertheless, there is still debate concerning the sources of these changes, incl...
Article
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Conflict resolution often involves mediators who understand the issues central to both sides of an argument. Mediators in complex networks represent key nodes that are connected to other key nodes in opposing subgraphs. Here we introduce a new metric, mediation centrality , for identifying good mediators in adversarial policy networks, such as the...
Preprint
Full-text available
The field of cognitive aging has seen considerable advances in describing the linguistic and semantic changes that happen during the adult life span to uncover the structure of the mental lexicon (i.e., the mental repository of lexical and conceptual representations). Nevertheless, there is still debate concerning the sources of these changes, incl...
Article
Full-text available
The recent rise in digitized historical text has made it possible to quantitatively study our psychological past. This involves understanding changes in what words meant, how words were used, and how these changes may have responded to changes in the environment, such as in healthcare, wealth disparity, and war. Here we make available a tool, the M...
Article
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There are well-understood psychological limits on our capacity to process information. As information proliferation-the consumption and sharing of information-increases through social media and other communications technology, these limits create an attentional bottleneck, favoring information that is more likely to be searched for, attended to, co...
Preprint
Understanding how societies have conceptualized risk throughout history may help to predict the public’s response to current and future threats and dangers. However, reconstructing what has been perceived as a risk over different historical periods is a thorny task. Previous investigations have commonly taken a qualitative approach. Complementing t...
Preprint
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Cognitive science invokes semantic networks to explain diverse phenomena from reasoning to memory retrieval and creativity. While diverse approaches are available, researchers commonly assume a single underlying semantic network that is shared across individuals. Yet, semantic networks are considered the product of experience implying that individu...
Article
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Years of research has shown that children do not learn words at random, but in distinct patterns. Why do we observe the patterns that we do? By using network science and investigating the words that children don’t learn, researchers have potentially uncovered a general property of word learning as a process of gap forming and filling. © 2018, The P...
Preprint
How, and how well, do people switch between exploration and exploitation to search for and accumulate resources? We study the decision processes underlying such exploration/exploitation tradeoffs by using a novel card selection task. With experience, participants learn to switch appropriately between exploration and exploitation and approach optima...
Article
Full-text available
Social diffusion of information amplifies risk through processes of birth, death, and distortion of message content. Dread risk—involving uncontrollable, fatal, involuntary, and catastrophic outcomes (e.g., terrorist attacks and nuclear accidents)—may be particularly susceptible to amplification because of the psychological biases inherent in dread...
Article
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Humor ratings are provided for 4,997 English words collected from 821 participants using an online crowd-sourcing platform. Each participant rated 211 words on a scale from 1 (humorless) to 5 (humorous). To provide for comparisons across norms, words were chosen from a set common to a number of previously collected norms (e.g., arousal, valence, do...
Conference Paper
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The focus of this paper is to examine differences in semantic network structure of late talkers and typical talkers to elucidate potential learning strategies used by late talking children. To address this question, we conducted network analysis on the vocabularies of 2,912 children, with 566 of those being late talkers. Contrary to previously repo...
Article
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We investigate how the mental lexicon changes over the life span using free association data from over 8,000 individuals, ranging from 10 to 84 years of age, with more than 400 cue words per age group. Using network analysis, with words as nodes and edges defined by the strength of shared associations, we find that associative networks evolve in a...
Conference Paper
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How does the mental lexicon, the network of learned words in our semantic memory, change in old age? To address this question, we employ a new network inference method to infer networks from verbal fluency data of a group of younger and older adults. We find that older adults produce more unique words in verbal fluency tasks than younger adults. In...
Conference Paper
Full-text available
How does the mental lexicon, the network of learned words in our semantic memory, change in old age? To address this question, we employ a new network inference method to infer networks from verbal fluency data of a group of younger and older adults. We find that older adults produce more unique words in verbal fluency tasks than younger adults. In...
Article
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Do properties of a word's features influence the order of its acquisition in early word learning? Combining the principles of mutual exclusivity and shape bias, the present work takes a network analysis approach to understanding how feature distinctiveness predicts the order of early word learning. Distance networks were built from nouns with edge...
Conference Paper
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Much problem-solving research has investigated if and why 'two heads are better than one', but typically posits that if there is any process gain observed it is because of the exposure to the ideas provided by another person's attempted solutions. This work fails to acknowledge or investigate what the interaction itself contributes to joint problem...
Article
In recent work exploring the semantic fluency task, we found evidence indicative of optimal foraging policies in memory search that mirror search in physical environments. We determined that a 2-stage cue-switching model applied to a memory representation from a semantic space model best explained the human data. Abbott, Austerweil, and Griffiths d...
Article
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Research on risky choice has been predominantly based on studies of choices between two alternatives, but their findings are often generalized to environments with more than two alternatives. One prominent claim of this research is that choices differ with respect to risk when alternatives are described (the description paradigm) as opposed to samp...
Article
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Concreteness-the psycholinguistic property of referring to a perceptible entity-enhances processing speed, comprehension, and memory. These represent selective filters for cognition likely to influence language evolution in competitive language environments. Taking a culturomics approach, we use multiple language corpora representing more than 350...
Article
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When searching for concepts in memory-as in the verbal fluency task of naming all the animals one can think of-people appear to explore internal mental representations in much the same way that animals forage in physical space: searching locally within patches of information before transitioning globally between patches. However, the definition of...
Article
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To what extent do people adapt their information search policies and subsequent decisions to the long- and short-run consequences of choice environments? To address this question, we investigated exploration and exploitation policies in choice environments that involved single or multiple plays. We further compared behavior in these environments wi...
Article
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Search can be found in almost every cognitive activity, ranging across vision, memory retrieval, problem solving, decision making, foraging, and social interaction. Because of its ubiquity, research on search has a tendency to fragment into multiple areas of cognitive science. The proposed topic aims at providing integrative discussion of the centr...
Article
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Bilingual first language learners face unique challenges that may influence the rate and order of early word learning relative to monolinguals. A comparison of the productive vocabularies of 435 children between the ages of 6months and 7years-181 of which were bilingual English learners-found that monolinguals learned both English words and all-lan...
Article
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The recent growth in crowdsourcing technologies offers a new way of envisioning student involvement in the classroom. This article describes a participatory action research approach to combining crowdsourced content creation with the student as producer model, whereby students’ interests are used to drive the identification and creation of educatio...
Article
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The capacity to adapt to resource distributions by modulating the frequency of exploratory and exploitative behaviors is common across metazoans and is arguably a principal selective force in the evolution of cognition. Here we (1) review recent work investigating behavioral and biological commonalities between external foraging in space and intern...
Article
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Facing a large set of alternatives has previously been reported to lead to choice overload, including choice deferral. Recent studies, however, imply that choice deferral is more tightly associated with the difficulty in evaluating alternatives than with set size: when alternatives are difficult to evaluate, people often defer a choice. This implic...
Article
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Search is a ubiquitous property of life. Although diverse domains have worked on search problems largely in isolation, recent trends across disciplines indicate that the formal properties of these problems share similar structures and, often, similar solutions. Moreover, internal search (e.g., memory search) shows similar characteristics to externa...
Article
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Are our memories of the world well described by the international news coverage in our country? If so, sources central to international news may also be central to international recall patterns; in particular, they may reflect an American-centric focus, given the previously proposed central U.S. position in the news marketplace. We asked people of...
Article
People can access information about choices in at least two ways: via summary descriptions that provide an overview of potential outcomes and their likelihood of occurrence or via sequential presentation of outcomes. Provided with the former, people make decisions from description; with the latter, they make decisions from experience. Recent invest...
Article
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Established psychological results have been called into question by demonstrations that statistical significance is easy to achieve, even in the absence of an effect. One often-warned-against practice, choosing when to stop the experiment on the basis of the results, is guaranteed to produce significant results. In response to these demonstrations,...
Article
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Prominent communication theories find a strong association between the news and our perception of the world. In this article, we compare the country names mentioned in the news with those recalled from the memory of individuals from four different nationalities: the United States, Israel, China, and Switzerland. Our findings suggest a more nuanced...
Article
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Null hypothesis significance testing (NHST) is the most commonly used statistical methodology in psychology. The probability of achieving a value as extreme or more extreme than the statistic obtained from the data is evaluated, and if it is low enough, the null hypothesis is rejected. However, because common experimental practice often clashes wit...
Conference Paper
We model the semantic recall sequences of 424 older adults aged between 69 to 103 years in the animal fluency task. Our results suggest that, under normal intellectual functioning, memory search in old age (69–84 years) is consistent with a dynamic process that switches between retrieval probes. With dementia and very old age (85–103 years), howeve...
Article
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Background: Many of the reproductive decisions that humans make happen without much planning or forethought, arising instead through the use of simple choice rules or heuristics that involve relatively little information and processing. Nonetheless, these heuristic-guided decisions are typically beneficial, owing to humans' ecological rationality -...
Article
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Three alternative mechanisms for age-related decline in memory search have been proposed, which result from either reduced processing speed (global slowing hypothesis), overpersistence on categories (cluster-switching hypothesis), or the inability to maintain focus on local cues related to a decline in working memory (cue-maintenance hypothesis). W...
Article
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A considerable amount of research has claimed that animals' foraging behaviors display movement lengths with power-law distributed tails, characteristic of Lévy flights and Lévy walks. Though these claims have recently come into question, the proposal that many animals forage using Lévy processes nonetheless remains. A Lévy process does not conside...
Article
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How do changes in choice-set size influence information search and subsequent decisions? Moreover, does information overload influence information processing with larger choice sets? We investigated these questions by letting people freely explore sets of gambles before choosing one of them, with the choice sets either increasing or decreasing in n...
Article
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Gonzalez and Dutt (2011) recently reported that trends during sampling, prior to a consequential risky decision, reveal a gradual movement from exploration to exploitation. That is, even when search imposes no immediate costs, people adopt the same pattern manifest in costly search: early exploration followed by later exploitation. From this isomor...